The inventive concept relates generally to nonvolatile memory devices and method of programming same. More particularly, the inventive concept relates to nonvolatile memory devices having variable resistance memory cells and methods of resetting same.
There is an increasing need for a nonvolatile semiconductor memory devices capable of realizing high integration and large data storage capacity. In particular, research has been directed to different types of nonvolatile memory devices that enable random data access. Such nonvolatile memory devices include the ferroelectric RAM (FRAM) that uses a ferroelectric capacitor, the magnetic RAM (MRAM) that uses a tunneling magneto-resistive film, the phase change memory device (PRAM) that uses Chalcogenide alloys, and the resistive RAM (RRAM) that uses a variable resistance material film as a data storage medium.
Of these, the RRAM characterized by high operating speeds, large data storage capacity, and low operating power. Thus, a great deal of ongoing research is directed to improvements in RRAM performance. As will be appreciated by those skilled in the art, the variable resistance material film of the RRAM exhibits a reversible resistance variation according to the polarity or amplitude of an applied control pulse. Examples of contemporary variable resistance material films include certain Colossal Magnetro-Resistive (CMR) materials with a Perovskite structure, and certain metal oxides forming a conductive filament.